Windows 7: Computer restarts after shutdown!! Please help!

I bought my sony vaio last year in April. I've been using it fine until about two weeks ago when it wouldn't go to sleep after i close the lid. (My computer's set to go to sleep if the lid is closed and it had always worked like that in the past ten months). After that, i can never shut it down or have it sleep.
I have to keep it charging all the time so it doesn't run out of battery by constantly staying on. And i can't even make it sleep. The screen just turns back on two seconds after i click sleep.
I have been googling for solutions and it seems like there's a lot of people who have or have had the same problem as me. However, I've tried so many solutions posted by other people and none of those worked for me so far. I have disabled automatic restart on system failures and i have also tried the clean foot. But even after I disabled all the start up services it still reboots two seconds after it seemingly shuts down.... And the only two ways to completely turn it off are holding the power button until it's off or taking out of the battery on the bottom of the laptop.

Can some experts help me with this problem? It's been driving me crazy in the past two weeks....